Drawing-press



R. S. SMITH. DRAWING PRESS. APPLICATION FILED III/III` a. I92o,

UNITED STATES PATENT OFFICE.

DRAWING-PRESS..

Speciicaton of Letters Patent.

Patented Feb. 15, 1921.

Original application led July 16, 1917, Serial No. 180,758. Divided andthis application led March 8,

` 19.20. Serial No. 363,957.

To all whom t may cof/wem:

Be it known that I, REUBEN STANLEY SMrrH, a citizen of the UnitedStates, and a resident of the cit of Milwaukee, county of Milwaukee, andtate of Wisconsin,r have invented certain new and useful Improvements inDrawing-Presses; and I do declare the following to be a full, clear, andexact description thereof, such as will enable others skilled in the artto which my invention pertains to make and use the same, ref erencebeing had to the accompanying drawings for a disclosure of oneconstruction in which the invention has been embodied.

The subject matter of the present application has been divided out of myprior application, Serial `:,.[:150,758, filed July 16, 1917, sincematured into Patent No. 1,338,335, April 27, 1920, to which patentreference may be had for a disclosure -of the generic aspects of myinvention.

The invention relates to drawing presses which are em loyed for theurpose of producing shape articles from I'Iat metal sheets. Inarticular,` the drawing press may be use in the production of the sidebars yof an automobile frame, which, as is well known, are formed fromsheet metal and have the formation of a channel bar, but the press .forthe purposes of this application to say that the press is provided withan eccentric mechanism which is actuated in proper timing so as to movethe unch to clamp the metal plate between t e punch and the knock-outplate usually employed in drawing presses, and which in my press, standsnormally flush with the top of the matrix, and that at or near thetermination of such clamping movement, a second set of eccentrics isactuated so as to continue the movement of the punch to force theclamped plate into the matrix of the press and perform the drawingoperation upon the plate, whereby the desired shape is imparted to thearticle formed from the said plate.

The eccentric mechanisms referred to are separately controlled in theiraction by a.

timing mechanism, as disclosed in the said patent, so that the clampingaction upon the metal plate is effected with rapidity of move-A ment ofthe punch, which clamping action 1s followed immediately by the retardedvoperatlon of the eccentric mechanism which imparts further movement tovthe punch to perform the drawing operation.

The surface of the bed of the press is formed as a smooth topped table,over which the plates may be manipulated without the interferenceheretofore encountered in drawing presses, by reason of mounting thematrix `and its adjunctive devices above the plane of the bed of thepress. To enable me to carry out the plan just described, I provide alongitudinal channel in the bed of the press, and in such channel Iplace the matrix, which, with the punch above referred to, constitutethe die members of the press. In drawlng presses as heretoforeconstructed, the matrix has been fitted in a shoe, which is attached tothe bed of the press. It has been required in such presses that the shoereferred to be of such proportions and strength as to enable it toresist the lateral stresses encountered in the operation of the press,and also that the sole of the shoe be of sufficient thickness, togetherwith the bed upon which the shoe is placed, to withstand any tendency tofracture under the crushing strains. But in my improved press the bed inwhich the' channel for the matrix is formed is so proportioned that allof the strains incident to the operation of the presses of ordinarycommon construction are effectively resisted and the causes forcomplaint are eliminated. I achieve this result by giving the bed of thepress a formation, which in cross-section resembles the letter C, whenpartly turned, and which possesses the highest elements of rigidity.

The knock-out plate is normally sustained so as to be flush with the topof the matrix, but such knock-out plate is actuated so as to retirewithin the matrix at a' ratewof speed which is coincident with thedescrlbed further advancing movement of the punch, f ollowing theclamping operation, and durmg which further movement the drawingoperation upon the metal plateis performed, but the clamping relationbetween the punch and theknock-out plate is maintained-during thedrawing operation.

In presses in which the side members of vthe matrixbare immovable orfixed with relation each other, it sometimes happens that inequalitiesexistingkin the metal sheet ""to *beV drawn, will lmpose very severestrains der such conditions, compression of the metal y, forming thesides of the channel bar takes place betweenthe punch and the sidemembers of the matrix, and the resistance thus interposed sometimesresults in disaster to the ress.

ith a view to relieving the press from the unusual strains which areexerted under the exigencies described, I have constructed the .Saidmatrix so that the side members thereof may have capacity for limitedmovement toward each other, such side members being actuated at or nearthe termination f of',v the drawing movement of the punch. In

carrying out this feature of my invention, I arrange the said sidemembers of the matrixso as to provide a slight clearance.y

between the matrix and the metal sheet as the punch forces the latterinto the matrix, thus permitting the metal plate to be drawn without theexpenditure of more than the power required to operate the press undernormal conditions. Through properly positioned actuating devices, I movethe side members of the matrix toward each other so as to exert a greatpressure with but little consumption of power, and squeeze the flangesof the drawn bar into contact with the sides of the punch, and thuscomplete the formation of the said bar by 'giving a permanent set tosaid anges. The provisions described enable me to obviate the dif#iculti'es heretofore referred to, and to complete the drawn articlewithout the use of the excessive force incident to the operation of theolder types of drawing presses.

To impart lateral movement to the side members of the matrix, I employ acrank mechanism which, with the consumption of a small amount of power,will actuate a toggle mechanism to exertv the necessary degree ofpressure upon the side members of the matrix and move them so as toimpart the desired squeezing pressure upon the side fianges of thechannel bar which has been formed from the blank in the matrix.

As in my said patent, the further movement of the punch to perform thedrawing operation is transmitted through the devices which -havepreviously brought the punch into clamping relation with the metal plateto be drawn into shape. That is to say, when the eccentric mechanism foreffecting the clamping movement has completed its operation, theeccentrics for effecting the drawing operation impart a further movementto the punch by bodily moving the first orY clamping eccentricmechanism.

Another feature embodied in my present invention is one wherein the-main operating parts, including the gears and the several Hoor linewith reference to which the press is set. A11 advantage which followsfrom this arrangement is that it enable's me to construct a press whichis accessible from all sides, without any interference by reason of thepresence of the shafts and gears at the sides and ends of the press, asheretofore.

Another advantage resulting from the construction just referred to, isthat I am enabled to maintain a constant shower of oil upon the severalactuating and operating mechanisms, and so provide an efficient meansfor lubricating the parts. The oil which drips from the severalmechanisms lmay be collected and filtered, and again used forlubrication.

In the drawings which accompany this specification,

Figure 1 is an end view showing in general outline the construction ofpress illustrated in my above mentioned application.

Fig. 2 is a sectional view through one side of the bed and matrix,showing in enlarged detail, one of the toggle mechanisms employed toimpart lateral movement ,tothe side members of the matrix, to effect theside squeezing operation described,

In the drawings, A indicates the main frame of the press, which may beintegrally formed, or it may be constituted of frame sections which willbe so secured together as to form a unitary structure. The base of thispress will rest at the bottom of a pit of suitable dimensions, and thedriving shafts and gears a-nd eccentric mechanisms will be placedentirely below the iioor line at the top of the pit, and with relationto which the press is set, so as to render the press accessible from allsides without interrup tion or interference. This arrangement furtherenables me to maintain a constant shower of oil either in the form of aspray, or in the form of streams directed upon particular parts, so asto effect an eiiicient lubrication of the parts, which in theiroperation are subject to considerable friction, by reason of the severestresses occurring in the press. To be able to lubricate the mechanismof the press in the manner described, is advantageous in that iteliminates the labor of periodic lubrication and further protects thepress against neglect in this important particulanvwum Surmounting themain frame, is the bed B of the press, which bed is channeledlongitudinally as-indicated at b, for the recep tion of the matrix sidemembers C, C1. In the construction illustrated, I have shown the saidmatrix members as supported upon angular carriers D, D1, in vthe anglesof which the respective matrix members C, C1,

-which cross head is mounted upon the upper ends of straining rods e,which latter are guided in vertical openings in the bed of the press. Asliding cross head E2 is connected to the lower ends of the strainingrods e. The cross heads E1 and E2, and the straining rods e, constitutea punch carrying frame, which is movable as a whole. The lowercross-head E2 is guided in the sides of the main frame, so that thepunch carrying frame may have a vertical reciprocation in a fixed path.

A second frame, composed of an upper` cross head F, a lower cross headF1, and straining rodsf, connecting the cross heads F and F1, is alsoguided for vertical recipro-- cation iIi the frame of the press, andis'likewise movable as a whole. The straining rods E of the punchcarrying frame pass through openings in the cross head F of the lowerframe, and the straining rods f of the lower frame pass throu h crosshead E2 of ne punch carrying frame. While-the said frames are eachcapable of independent movement, they have a joint movement at times, aswill be described later. v

The straining rods e, e, uniting the cross-y heads E1, E2, as well asthe straining rods f, f, uniting the crossfheads F, F1, are threaded attheirends for the reception of huts, which bear upon the upper and lowersides of the respective cross-heads, so as to provide an exactadjustment of the punch E with reference to the matrix of the press,

and correspondingly define the movements of the punchunder the influenceof the eccentrics.

The driving shaft G is journaled at one side of the frame and carries apinion g meshing with a gear g1, 'upon the axis of which is fixed apinion g2, meshing with a gear g3 which latter carries a pinion g". Uponthe axis of the gear g3 and pinion g4. a radial arm g5 is mounted, thesaid arm supporting at its outer end a stud ge, upon which rotates agear 97, in mesh with the pinion g2 previously described. A floatinglever g2 is supported upon the stud g", and extends to the exterior ofthe press. At its inner end, the fioating lever supports an eccentricshaft g1 j ournaled in the cross head F, of the lower frame.

Keyed upon the eccentric shaft is a gear g10 which meshes with an idl'egear 911 carried by the ioating lever and in mesh with the gear g7.Through the connections described, motion is transmitted from thedriving shaft to the eccentric shaft, The

openings in the lowertrain of gears will be duplicated at the other endof the press, and connected by suitable shafting. Several eccentrics,one of which, indicated g12, are mounted on the eccentric shaft g, andare connected by eccentric links g, to the lower cross heads e2 of thepunch carrying frame.

The surface of the bed B is formed' as a smooth topped table, free fromprojections.

The matrix members C and C1, and their supporting carriers D, D1, lieflush with the surface of the bed. A knock-out plate e1 is normallysupported with its face iiush with that of the matrix, as shown in Fig.' 1. Knock-out pins e2, guided in vertical openings in the bed B,support the knock-out plate e1' at their upper ends, and the 'lower endsof the said knock-out pins rest upon a plane surface formed upon the topof the cross head F. In such position, the knockout pins e2 serve asthrust rods to maintain at all times a fixed distance between theknock-out plate e1 and the plane surface e1 of the cross head F.

The pinion g on the driving shaft G also meshes with a gea-r h, on thehubof which is fixed a pinion h1, meshing with a gear h3, which carriesa pinion h2, which in turn meshes with a gear h5, mounted upon an ec-Icentric shaft k6, journald in a fixed cross bar of the main frame. Theeccentric shaft it is provided with eccentrics h1, which latter areconnected by links ha, to the cross head F1 of the lower frame.

In the operation of the press, a metal blank w is ed intothe press andproperly ioo positioned over the matrix.4 The speed of rotation of theeccentric shaft g2, is such that the eccentrics 912, carried thereby,impart a comparatively quick movement to the punch carrying frame tobring the punch'E into clamping relation with the blank resting upon theknock-out plate 1, and supported also upon the face of the matrix. Thisclamping relation is established as the eccentrics 912 reach the end oftheir throw. The reducing gears leading to the'eccentric shaft h are soproportioned that a relatively slowrmovement is imparted bv theeccentrics h1 to the drawing frame. Just as the eccentrics g12completetheir throw, the eccentrics h1 commence their operation, andltransmit a further 'but retarded movement to the punch carrying framethrough the now distended eccentric links g, the shaft g, and the lowercross bar E2 of the punch carrying frame. During the downward stroke ofthe eccentrics h", the punch carrying frame and the drawing frame movejointly as a single construction, whereby the punch in its furthermovement intoy vthe matrix under the action of the eccentrics h1, forcesthe metal blank m into the matrix, and folds the sides thereof againstthe sides of the punch so as to form the said metal blank into a channelbar.

From the time that the punch has reached its position of clampingrelation with the blank and the knock-out plate e1, the said relationdoes not change until after the drawing operation has been performed.The punch E and the cross head F move at the same relative speed duringthe drawing operation, and the knock-out platee1 being sustained by theknock-out rods, the blank m is rmly clamped between the punch and theknock-out plate e1 during the whole of the drawing operation. Theadvance of the punch AE to force the blank into the matrix, isaccompanied by the simultaneous retirement of the knock-out plate e1, byreason of the movement of the cross head F under the action of theeccentrics 7L7,.and when the latter have passed their dead center, thewithdrawal of the punch will be closely followed bythe movement of theknock-out plate e1, to ejectthe channel bar from the matrix. Theclamping relation between the punch and the knock-out plate is broken atthe moment that the knock-out plate reaches its normal elevated positionin line with the face of the bed, and the punch is raised to its highestposition by reason of the eccentrics g12 havmg passed their dead centeron their longer throw, and through their connected straps g13 are actingto lift the punch carrying frame. 'l

In ldrawing presses as usually constructed heretofore, a singleset ofeccentrics or crank mechanism has been used to impart both clampingmovement and the drawing movement to the punch. In such older mechanism,the punch effect-s its clamping 'engagement with the metal blank at atime of comparatively rapid movement ofthe punch, with the result thatthe punch forces the metal blank into the matrix with a sudden blow,which occurs with such force and rapidity that time is not allowed forthe necessary molecular changes in the structure of the metal to takeplace,l and this frequently is productive of an uneven or unequaldistortion which weakens the bar along the line of the bend. But in myapproved press, the compound motion which employ enables me to effectthe clamping action upon the blank with rapidity, and to instantly startthe drawing operation at its lowest relative speed. The result of theoperation of my press is that at the commencement of the drawingoperation, the molecular construction of the metal blank has anopportunity to adjust itself to the change` so that the drawingoperation may be performed upon theblank and so obviate the liability tothe damage heretofore usually incurred. As indicated at the beginning ofthis specification, it sometimes happens that inequalities inthe metalblanks impose severe strains upon the construction of the press when thepunch starts to force the blank into the matrix. Such contingenciesrequire the expenditure of more than the power required to operate thepress under normal conditions, and disaster to the press sometimesresults. VI have found that by constructing the press so that the sidemembers of the matrix are disposed at a distance from the punch a littlein excess of the thickness of the blank to be drawn, that the punch mayforce the metal blank into the matrix with no unusual effort, and thatby providing means for taking up the clearance by constructing the sidemembers of the matrix with capacity for movement toward each other, thesides of the drawn bar may be squeezed against the sides of the punch,to complete the formation of such bar.

To enable me to perform this operation of exerting a side pressure onthe flanges of the channel bar, I have mounted a pair of longitudinalshafts H, H1,.in the bed of the press, and have fixed upon the saidshafts a series of cams or toggle members 7L1, which are adapted uponthe partial rotation of the said shafts, to impart their thrust to othertoggle members 7&11, which bear against sliding blocks k12 mounted inchannels 71,13 in the bed of the press. The sliding blocks k12 abutdirectly against the matrix members C and C1, or against the carriers Dand D1, in case the latter are employed to support the matrix members.

The parts described are operated for the purpose stated, at theconclusion of the drawing movement of the punch, and act to compress theflanges of the channel bar between the punch and the matrix members,whereby a permanent set is given to the said flanges. This squeezingmotion is followed by a quick relaxation of the pressure, and leaves thewithdrawal of the punch and the ejection of the channel bar from thematrix to be performed freely, and without having to overcome thefrictional resistance existing between the punch, the blank and thematrix in drawing presses of the older type.

I have provided a simple means for effecting the lateral movement of thematrix members just described. The rock shafts H and H1, are providedwith radial levers 7L14 and 71,15 connected at their ends by a toggle7L, which latter is operated by a link 7L17 connected at its" other endto one arm of a bell crank lever 71,18, the other arm of which isconnected by means of a rod 7t19 to a. crank 7L20 mounted axially with agear 7a11 driven 'by a pinion M2, fixed on the driving shaft G beforereferred to.

It will be observed that the' bed of the press has in cross-section thegeneral outline of a letter C, turned on its axis.

The proportions embodied in the formation of the bed of the press aresuch that the opposing strains are resisted much more eifectively thanin the common types of similar presses, in which the matrix is set in ashoe which is mounted upon the bed of the press, and over which 'thework must be lifted.

Having thus described my invention, what I claim and desir@l to secureby Letters Patent ofthe United States, is:

1. In a drawing press, the combination with a set of coperative workshaping members, of crank motion mechanism adapted to effect a relativeapproach of said members for one operation, and separately acting crankmotion mechanism adapted to impart a further movement of said members inthe same direction for a second operation, one of said members beingformed in laterally movable sections, and means for imparting relativemovement of said sections towardy each other subsequent to theappreaching movements of said members.

2. In a drawing press, the combination with a matrix provided withlaterally movable side walls, a knock out plate normally supportedbetween the upper margins of said side walls, a punch motion mechanismadapted to actuate .said punch into work clamping position withreference to the knock out plate, separately acting crank motionmechanism for additionally actuating said punch and also the knock outplate toward the base of the matrix for a work shaping operation, meansfor subsequently moving said matrix walls toward each other to press thework upon;the sides of said punch, and means Jfor retracting said sidewalls and subsequently retracting the punch and the knock out plate totheir initial positions.

i the knock out plate, separately acting crank. v

3. In a drawing press, the combination with a matrix provided withlaterally movable side walls, a knock out plate normally supportedbetween the upper margins of said side walls, a punch, crank motionmechanism adapted to actuate said punch into work clamping position withreference to motion mechanism for additionally actuating said punchl andalso the knock out plate toward the base of the matrix for a workshaping operation, toggle mechanism for subsequently moving said matrixwalls toward each other to `press the workupon the sides of said punch,and means forretracting said side walls and subsequently retracting thevpunch and the knock out plate to their with a relatively stationarymatrix having initial positions.

4. In a drawing press, the combination with a matrix provided withlaterally movable side walls, a knock out plate normally supportedbetween the upper margins of said side walls, a punch, crank motionmechanism adapted to actu-ate said punch into work clamping positionwith reference to the knock out plate, separately acting crank motionmechanism for additionally actuating said unch and also the knock outplate toward t e base of the matrix for a w'ork shaping operation,toggle mechanism for subsequently moving said matrix walls toward eachother rto press the work upon the sides of said punch, means forretracting said side walls and subsequently retracting the punch andthe'knockeout plate to their initial positions, and meansfor automati--cally initiating the work clamping, work shaping, pressing, andretracting operations in sequence.

5. In a metal working press, a frame supporting a fixed bed at the topthereof and extending below the floor line above which the bed islocated, a head reciprocating over the bed, straining rods connected tothe head and guided for vertical movement by the bed, a driving shaftwith eccentric connections to the straining rods to actua-te the saidhead, said shaft and connections being supported in -the frame below thefloor line, so as' to afford unobstructed access to the press from allsides, and enable rthe actuating mechanism tobe lubricated by an oilspray.

6. In a drawing press, a reciprocating punch, a iixed bed having achannel in which the matrix is set tot form a flush-top workv table,movable sides for the matrix, and devices within the bed for actuatingthe said movable sides, to supplement the punch and matrix in shapingthe work.

7. In a drawing press, the combination with a relatively stationarydivided matrix having side walls adapted to approach and recede fromeach other, a punch, means for actuating the punch linto the matrix fora work shapin operation, and means for-actuating the side walls of thematrix toward each other upon completion of the work shaping operationsof the punch.

8. In a drawing press, they combination with a relatively stationarydivided matrix having side wallsadapted to approach and recede from eachother, a punch, means Jfor actuating the punch into the matrix for awork shaping operation, and means for actuating the side walls of thematrix toward each other. upon completion of the work shaping operationyof the punch, said side walls being held in a relatively fixed positionduring the work shaping operation of' the punch.

9. In a drawing press, the combination 10. In a drawing press, thecombination of a set of cooperating Work shaping members, mechanismadapted to effect a lrelative approach of said members for oneoperation, separately lacting mechanism adapted to produce a furtherrelative movement of said members for a second operation, one of saidmembers being formed in laterally movable sections, and means for movingsaid sections toward eachother upon the completion of the said secondmovement of' the work shaping members.

11. In a press for drawing metal plates into shape, a frame, a punch anda matrix, a bed forming a work table supported o-n the top of the frame,means comprising gears and eccentrics for actuating the punch arrangedand connected thereto below the floor line with reference to which thepress is located, whereby the bed is rendered accessible from all sideswithout obstruction by said actuating means, and whereby such floor linewith reference to which the press is set, a punch working over the bed,a punch carrying frame guided by the bed and extending below the floorline, and actuating mechanism for vertically moving the punch carryingframe, said mechanism being positioned below the said floor line,whereby the bed of the -press is accessible at all sides Iandlubrication of the punch actu,- ating mechanism may be effected by anoil spray.

13. In a drawing press, a punch, a fixed bed having a channel in whichthe matrix is set to form a smooth topped table over which the work maybe moved, said matrix composed of movable side members, and means foractuating the matrix members to supplement the action of the punch inshapin the work.

n testimony whereof, I have signed my name at Milwaukee, this 3d day ofMarch, 1920.

R. STANLEY SMITH.

Witnesses:

W. F. WooLARD, C. THEO. Osrnnnns.V

